Viral particles similar to non occluded baculoviruses were isolated from penaeid shrimp Penaeus chinensis in China. The size of enveloped virion is 250-300×110nm.After extraction,the viral DNA was digested by EcoRⅠ and cloned into the pUC 18. Two clones, L46 and M13,containing inserts of 2.14kb and 3.58kb in size respectively, were obtained.The inserts were labeled by Digoxingenin. Diseased shrimp samples issued from different regions of China were investigated by dot blot hybridization with the previously preparing probes L46, M13 and with A26 probe. All the probes reacted with the tested samples showing baculovirus infection. It indicated that baculovirus from P.chinensis is very close to the WSSV.